How many Sulfur atoms are in 0.42 mol S?

1 Answer
Nov 9, 2015

Answer:

If I have half a dozen sulfur atoms; clearly I have 6 sulfur atoms. If I have 0.42 mol of sulfur there are #0.42 xx N_A# sulfur atoms, where #N_A =# Avogadro's number.

Explanation:

The mole is simply a number, admittedly a very large number: #N_A = 6.022 xx 10^(23)#. So, in fact I have #0.42 xx N_A# sulfur atoms.

To expand, Avogadro's number, #N_A#, is simply the link between the micro world of atoms and molecules, with the macro world of grams and kilograms. If I have a mass of #32.06# #g# of sulfur, which I can easily weigh out on a bench, I know, to a very good approximation, that I have #6.022 xx 10^(23)# sulfur atoms (these may be individual atoms or they may be part of #S_8# rings - the number of sulfur atoms is determined directly!)